Process for breaking petroleum emulsions



l atented July I, 1952 uuirso srsrrs;

TEN? GFFME to Petrolite Corporation, Ltd., Wilmington, DeL, a corporation of Delaware No Drawing. Application September 5, 1950 Serial No. 183,291

11 Claims.

This invention relates to petroleum emulsions of the water-in-oil type that are commonly referred to as cut oil, roily oil, emulsified oil, etc., and which comprise fine droplets of naturally-occurring waters or brines dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion.

One object of my invention is to provide a novel process for breaking or resolving emulsions of the kind referred to.

Another object of my invention is to provide an economical and rapid process for separating emulsions which have been prepared under controlled conditions from mineral oil, such as crude oil and relatively soft waters or weak brines. Controlled emulsification and subsequent demulsification under the conditions just mentioned, are of significant value in removing impurities particularly inorganic salts from pipeline oil.

Demulsification as contemplated in the present application includes the preventive step of cornmingling the demulsifier with the aqueous component which would or might subsequently become either phase of the emulsion, in absence of such precautionary measure. Similarly, such demulsifier may be mixed with the hydrocarbon component.

The demulsifyin agent employed in the present process is a fractional ester obtained from a polycarboxyy acid and a diol obtained by the oxypropylation of dihydroxylated ethers of glycerol with the proviso that the ether radical in turn be free from any group having 8 or more carbon atoms and is preferably obtained from a watersoluble aliphatic alcohol but may be obtained from an alicyclic alcohol such as cyclohexanol or from a phenol such as hydroxybenzene or cresol.

A monohydric compound having less than 8 carbon atom such as methyl alcohol, ethyl al oohol, propyl alcohol, allyl alcohol, butyl alcohol, phenol, methyl phenol, hexanol, methyl hexanol, cresol, benzyl alcohol, cyclohexyl methyl alcohol, tetrahydrofurfuryl alcohol, or tetrahydropyran- Z-methanol, can be treated with several moles of ethylene oxide or propylene oxide to yield ether alcohols. Such ether alcohols can be treated with glycide to give ether diols of the kind herein employed as initial materials. Other well known procedures can be employed, as for example, such etherized monohydric alcohols can be reacted with epichlorohydrin in presence of caustic soda or as a subsequent step so as to reform the epoxy ring; such compound can then be subjected to reaction with water so as to rupture the epoxy ring. Other proceduresemployed in the preparain which n and n are numerals including zero, and n is a small whole number less than 10, with the proviso that n plus 11/ plus 71'' equals a sum varying from 15 to and n" is a whole number not over 2; R." is an alkylene radical having 2 to 3 carbon atoms, R is a hydrocarbon radical having less than 8 carbon atoms, and R is a radical of the polycarboxy acid.

in which n" has its previous significance; and with the further proviso that the parent diol prior to esterification be water-insoluble and kerosenesoluble.

Attention is directed to the co-pending application of C. M. Blair, Jr., Serial No. 70,811, filed January 13, 1949 (now Patent No. 2,562,898, dated August 7, 1951), in which there is described, among other things, a process for breaking petroleum emulsions of the water-in oil type characterized by subjecting the emulsion to the action of an esterification product of a dicarboxylic acid and a polyalkylene glycol in which the ratio of equivalents of polybasic acid to equivalents of polyalkylene glycol is in the range of 0.5 to 2.0, in which the alkylene group has from 2 to 3 carbon atoms, and in which the molecular weight of the product is between 1,500 to 4,000.

Similarly, there have been used esters of dicarboxy acids and polypropylene glycols in which 2 moles of the dicarboxy acid ester have been reacted --with one mole of a polypropylene glycol having a molecular weight, for example, of 2,000 so as to form an acidic fractional ester. Examination of what is said subsequently herein as well as the hereto appended claims in comparison with the previous example will show the line of plied by an aliphatic alcohol, preferably having at least 3 carbon atoms and being water-soluble, such as propyl alcohol, butyl alcohol, or ar'nylalcohol. In the case of butyl or amyl alcohols some of the isomers are water-soluble to the extent that they show solubility of at least a few percent atroom temperature.

My preference, purely as a matter of convenience, is to obtain such etherized diols of thekindj herein described from monohydric ether alcohols and glycide. Various monohydric ether alcohols suitable for reaction with glycide are available commercially. These include propyleneglycol methyl ether, dipropyleneglycol methyl ether, tripropyleneglycol methyl ether, propyleneglycol ethyl ether, dipropyleneglycol ethyl ether, tripropyleneglycol ethyl ether, propyleneglycol isopropyl ether, dipropyleneglycol isopropyl ether, tripropyleneglycol isopropyl ether, propyleneglycol n-butyl ether, dipropyleneglycol n-butyl ether, and tripropyleneglycol n-butyl ether. Similar compounds are available in which ethylene oxide radicals replace the propylene oxide radicals, and, similarly, one can readily prepare compounds in which a mixture of ethylene oxide and propylene oxide is used to react with one or more of the monohydric compounds previously mentioned, and particularly the alcohols, such as the water-soluble aliphatic alcohols. Reference to the hydrocarbon radical, of course, includes the variety of alcohols which contain an oxygen atom as in the case of tetrahydrofurfuryl alcohol, tetrahydropyran-Z-methanol, etc., for the reason that the presence of the oxygen atom does not .detract from the characteristic property imparted by the presence of a hydrocarbon radical. Reference to R. in the specification and the claims as being a hydrocarbon radical of course includes such radicals as those derived from these last two alcohols.

For convenience, what is said hereinafter will be divided into five parts:

Part 1 is concerned with the preparation of the oxypropylation derivatives of the glycerol ether type of diol;

Part 2 is concerned with the preparation of the esters from the oxypropylated derivative;

Part 3 is concerned with aconsideration of the structure of the glycerol ether type of diols which is of significance in light of what is said subsequently,

Part 4 is concerned with the use of the products herein described as demulsifiers for breaking water-in-oil emulsions; and

Part 5 is concerned with certain derivatives which can be obtained from the oxypropylated diols. In someinstances, such derivatives are obtained by modest oxyethylation preceding the oxypropylation step, or oxypropylation followed by oxyethylation. Thi results in diols having somewhat different properties which can then be reacted with the same polycarboxy acids or anhydrides described in Part 2 to give effective demulsifying agents. For this reason a description of the apparatus makes casual mention of oxyethylation. For the same reason there i brief mention of the use of glycide. V

4 PART 1 For a number of well known reasons equipment, whether laboratory size, semi-pilot plant size, pilot plant size, or large scale size, is not as a rule designed for a particular alkylene oxide. Invariably and inevitably, however, or particularly in the case of laboratory equipment and pilot plant size the design is such as to use any of the customarily available alkylene oxide, i. e., ethylene oxide, propylene oxide, butylene oxide, glyclde, epichlorohydrin, styrene oxide, etc. In the subsequent description of the equipment it becomes obvious that it is adapted for oxyethylation as well as oxypropylation.

Oxypropylations are conducted under a wide variety of conditions, not only in regard to presence or absence of catalyst, and the kind of catalyst, but also in regard to the time of reaction, temperature of reaction, speed of reaction, pressure during reaction, etc. For instance, oxyalkylations can be conducted at temperatures up to approxiamtely 200 C. with pressures in about the same range up to about 200 pounds per square inch. They can be conducted also at temperatures approximating the boiling point of water or slightly above, as for example to C. Under such circumstances the pressure will be less than 30 pounds per square inch unless some special procedure is employed as is sometimes the case, to wit, keeping an atmosphere ofinert. gas such as nitrogen in the vessel during the reaction. Such low-temperatureelow reaction rate o ypropylations have been described very completely in U. S. Patent No. 2,448,664, to H. R. Fife ,et al., dated September 7, 1948. Low temperature, low pressure Oxypropylations are particularly desirable where the compound being subjected to oxypropylation contains one, two or three points of reaction only, such as monohydric alcohols,g-lycols and triols.

.Since low pressure-low temperature. reaction speedoxypropylations require considerable time, for instance, 1 .to 7 days of 24. hours each to complete'the reaction they are conducted as a rule whether on a laboratory scale, pilot plant's cale. or large scale, so as to operate automatically. The prior figure of seven days applies especially to large-scale operations. Ihave used conventional equipment with two added automatic features: (a) a solenoid controlled valve which shuts off the propylene oxide in event that the temperature gets outside a predetermined and'set range, for instance, 95 to 120 C., and (b) another solenoid valve which shuts off the propylene oxide (or for that matter ethylene oxide if itds being used) if the pressure gets beyond a predetermined range, such as 25 to 35 pounds. Otherwise, the equipment issubstantially the same as iscommonly employed for this purpose where the pressure of reaction ishigher, speed of reaction is higher, and time of reaction is much shorter. In such instances such automatic controls are not necessarily used.

Thus, in preparing the various examples I have found it particularly advantageous to use laboratory equipment or pilot plant which is designed to permit continuous oxyalkylation whethe er it be oxypropylation or oxyethylation. With certain obvious changes the equipment canbe used also to permit oxyalkylation involvingthe useof glycide where no pressure is involvedexcept the vapor pressure of. a solvent, if any, which may have been used as a diluent.

As previously pointedout the methodoi using propylene oxide is the same as ethylene oxide. point is emphasized only for the reason that theapparatus is so designed and constructed as touse either oxide.

The oxypropylation procedure employed in the preparation of the oxyalkylated derivatives has been uniformly the same, particularly in light of the fact that a continuous automatically-controlled procedure was employed. In this procedure the autoclave was a conventionalautoclave made of stainless steel and having a capacity of approximately 15 gallons'and a working pressure of one thousand pounds gauge pressure. This pressure obviously is far beyond any requirement as far as propylene oxide goes unless there is a reaction of explosive violence involved due to accident. The autoclave was equipped with the conventional devices and openings, such as the variable-speed stirrer operating at speeds from 50 R. P. M. to 500 R. P. M.; thermometer well and thermocouple for mechanical thermometer; emptying outlet; pressure gauge, manual vent line; charge hole for initial reactants; at least one connection for introducing the alkylene oxide, such as propylene oxide or ethylene oxide, to the bottom of the autoclave; along with suitable devices for both cooling and heating the autoclave, such as a cooling jacket, and, preferably, coils in addition thereto, with the jacket so arranged that it is suitable for heating with steam or cooling with water and further equipped with electrical heating devices. Such autoclaves are, of course, in essence small-scale replicas of the usual conventional autoclave used in oxyalkylation procedures. In some instances in exploratory preparations anautoclave having a smaller capacity, for instance, approximately 3 /2 liters in one case and about 1% gallons in another case, was used.

Continuous operation, or substantially continuous operation, was achieved by the use of a separate container to hold the alkylene oxide being employed, particularly propylene oxide. In conjunction with the smaller autoclaves, the container consists essentially of a laboratory bomb having a capacity of about one-half gallon, or somewhat in excess thereof. In some instances a larger bomb was used, to wit, one having a capacity of about one gallon. This bomb was equipped, also, with an inlet for charging, and an eductor tube going to the bottom of the container so as to permit discharging of alkylene oxide in the liquid phase to the autoclave. A bomb having a capacity of about 60 pounds was used in connection with the 15-gallon autoclave. Other conventional equipment consists, of course, of the rupture disc, pressure gauge, sight feed glass, thermometer connection for nitrogen for pressuring bomb, etc. The bomb was placed on a scale during use. The connections between the bomb and the autoclave were flexible stainless steel hose or tubing so that continuous weighings could be made without breaking or making any connections. This applies also to the nitrogen line, which was used to pressure the bomb reservoir. To the extent that it was required, any other usual conventional procedure or addition which provided greater safety was used, of course, such as safety glass protective screens, etc.

Attention is directed again to what has been said previously in regard to automatic controls which shut off the propylene oxidein event temperature of reaction passes out ofthe predetermined range or if pressure in the autoclave passes out'of predetermined range; I

With this particular arrangement practically all oxypropylations become uniform in that the reaction temperature was held within a few degrees of any selected point, for instance, if C. was selected as the operating temperature the maximum point would be at the most C. or 112 C., and the lower point would be 95 or possibly 98 C. Similarly, the pressure was held at approximately 30 pounds within a 5-pound variation one way or the other, but might drop to practically zero, especially where no solvent such as xylene is employed. The speed of reaction was comparatively slow under such conditions as compared with oxyalkylations at 200 C. Numerous reactions were conducted in which the time varied from one day (24 hours) up to three days ('72 hours), for completion of the final member of a series. In some instances the reaction may take place in considerably less time, i. e., 24 hours or less, as far as a partial oxypropylation is concerned. The minimum time recordedwas about a 3-hour period in a single step. Reactions indicated as being complete in 10 hours may have been complete in a lesser period of time in light of the automatic equipment employed. This applies also where the reactions were complete in a shorter period of time, for instance, 4 to 5 hours. In the addition of propylene oxide, in the auto clave equipment as far as possible the valves were set so all the propylene oxide if fed continuously would be added at a rate so that the predetermined amount would react within the first 15 hours of the 24-hour period or two-thirds of any shorter period. This meant that if the reaction was interrupted automatically for a period of time for pressure to drop or temperature to drop the predetermined amount of oxide would still be added in most instances well within the predetermined time period. Sometimes where the addition was a comparatively small amount in a 10-hour period there would be an unquestionable speeding up of the reaction, by simply repeating the examples and using 3, 4, or 5 hours instead of 10 hours.

When operating at a comparatively high tem-- perature, for instance, between 150 to 200 C., an. unreacted alkylene oxide such as propylene oxide, makes it presence felt in the increase in pressure or the consistency of a higher pressure. However, at a low enough temperature it mayhappen that the propylene oxide goes in as a liquid. If so, and if it remains unreacted there is, of course, an inherent danger and appropriate steps must be taken to safeguard against this possibility; if need be a sample must be withdrawn and examined for um'eacted propylene oxide. One obvious procedure, of course, is to oxypropylate at a modestly higher temperature, for instance, at to C. Unreacted oxide affects determination of the acetyl or hydroxyl value of the hydroxylated compound obtained.

The higher the molecular weight of the compound, i. e., towards the latter stages of reaction, the longer the time required to add a given amount of oxide. One possible explanation is that the molecule, being larger, the opportunity for random reaction is decreased. Inversely, the lower the molecular weight the faster the reaction takes place. For this reason, sometimes at least, increasing the concentration of the catalyst does not appreciably speed up the reaction, particularlywhen the product subjected to oxyalkylation has a comparatively high molecular weight; However, as has. been pointed out previously, operating at a low pressure and a low tempera's tu'reever-1 in large .scaleoperations as muoh as a week Often days time may lapse to obtain some ot the-higher molecular weight derivatives from monohydric or 'dihydric materials. I

- In'- a number of operations the counterbalance scale or-dial- -scale holding the propylene oxide bomb-was so set that when the 'pred'etermi'ned amount of propylene oxide had passed into the reaction the scale movement through a time operating device was set for either one to two heui 's so that r'eaction continued for 1 to 3 hours after the final addition of the last propylene oxide and thereafter the operation was shut down. This gzia'rti'cular device is particularly suitablefor' use on larger equipment than laboratory size autoclaves, to wit, on semi-pilot plant or pilot plant size, as well as on large scale s iZe. This final st'irring period i's-inte'nded' to avoid the presence of unre'acte'd oxide.

In this sort of operation, of course, the ternperature range was controlled automatically by either use of cooling water, steam, or electrical heat, so as to raise or lower the tem erature. The pressuring of the propylene oxide into the reaction vessel was also automatic insofar that the 'feedstream was set fora slow continuous run which was shut off in case the pressure passed a p'red'etermined point as reviously set out. All theiooir'its of design, construction, 1 etc., were cohventional'includin'g the gases, 'che'ck valves and entire equipment. As far as I am-aware at least two firms,-and possibly three, specialize in auto-'- clave e uipment'suc'h as I have employed in the laboratory; and are prepared to furnish-equipmerit of: this same kind. similarly pilot'plant equipment is available. This point is simply made as a precaution in the direction of safety. Oxyalkyla'tions, particularly involving ethylene oxide glycide, propylene oxide, etc, should not be -conducted except in equipment specifically designed for'the purpose.

Actually oxypr'opylations of diols of various kinds-can be conducted in all sizes of equipment, and the only matters involved are (a) convenience, '(b) economy, and (c) the fact that the actual molecular weight based on the hydroxyl number drops on rapidly from the theoretical molecular weight, based on the assumption of complete reaction. This applies to substantially every variety "of diol which I have examined, particularly as-far as oxypropylation goes, and usually to a mixed diol obtained by a combination of ethylene oxide and propylene oxide. The higher the temperature of reaction the reater this difference; the higher the speed of reaction usually the greater this difierence. In other words, everything else being equal, the lower the temperature of reaction and the slower the speed of reaction, provided that no unreacted oxide remains behind, the more quickly the actual hydroxyl value will approach the theoretical. In addition to what has been said previously other procedures as'illustrated by the following sixteen examples can be used but again it is purely a matter. of choice and variation.

Example 1a Thesdiolemploye'd was the glycidyl ether of tripropy'leneglycol isopropyl ether. One mole of the 'monoh'y'dric ether was reacted in presence of;2% sodium-methylate with one mole of glycide until the reaction was complete.- The resultant productas previouslynoted, is the glycidyl' ether ofitripropyleneglycol isopropyl ether. Its molecularxweight is; 308; The particular autoclave g. employedwasoneewith a eapaoityof a little over 5 gallonsor' on'thea'vera'ge of about 40 pounds ofreaction mass. The speed 'of the stirrer could be varied from to 350 R. P. M. '6 /6 pounds of the glycidyl ether-,previously referred to, was chargedinto-t-he autoclave along with .50 pound of sodium hydroxide. The reaction pot was flushed out with nitrogen. The autoclave was Sealed and theautomatic devices adjil'Ste d and set for injecting 23.20 pounds of propylene oxide in approximateiys hours, with an allowance of another hour fer stirring to insure completeness of reaction. The'pressure regulator was set for a maximum o'f 35 pounds per square inch. This meant that the bulk or the reaction could take place, and probably "didtake place, at a comparetively low-pressure. This comparatively low pres: sure was the result of the fact that considerable catalys't wa's present. The propylene oxide was added at therate of about 8 pounds per hour. More important; the selected temperature range was 205 to 215 F. (about the boiling point-of water). The initial introduction of propylene oxide was not started until the heating devices hadraised the temperature to about the boiling point-of water. At the completion or the r'eacf tion the molecular weight, based on the hydroxyl value determination, was 850 compared with a theoretical molecular weightof 1468. The final product was water-soluble, xylene-soluble, and somewhatdispersible in'part inkerosene. How= ever, the bulk or the product was kerosene in= soluble;

E'aia'mpl' 2a In this instance and in the next five examples (Examples 3a through 711, inclusive) the auto clave used was a 15-gallon autoclaveandnot a 5-gal1on autoclave. The equipment and design of the IS -gallon autoclave was the same as" that of the 5-'gall0n autoclave. The-same procedure was employed as in Ex ample 1a,. preceding, as far as the initial re= actant used and the amount of the initial re actant. The amount of catalyst addedwas 10 ounces. The time period was a proximately 4 hours-with an added hour for's'tiriing The con ditions of temperature and pressure were the same as in Example 1a, preceding. Theox'ide (34.80 pounds) was added at about the sam'rate, abouts pounds per'hour. requiring a little over 4 hours, with a 45-minute stirring period afterwards:

The molecular Weight, based on a hydroxyl de termi'nation, was 1125 compared with the the: or'eticall molecular weight (if 2048. The'p'r'oduct was watereinsoliible, xylene-soluble and kerosenesoluble. This statement applies also to the next six examples and will not be repeated.

Incidentally, the appearance of all these prom ucts varied from rather viscous, colorless or s-tr'aw oolore'd compounds, to others ha'vifig a distinctainb'erfcolor. Those of the highest molestilar weight would hardly flow at ordinary teiii= perature, or at least were rather viscous. or convenience I have Stored samples in wide-mouth cans. This applies to all theva-r'ious' sampls herein described and this statement will..tli'e're fore, not be repeated.

propylene oxide added was 46.4 pounds. .The time period-employed was 6 hours with an added hour for stirring. The conditions of temperature and pressure were the same as in the preceding examples and, as a matter of fact, apply to all subsequent examples in this series, i. e., Examples 4a through 8a, so this information will not be repeated.

The final product showed a molecular weight; based on hydroxyl number, of 1375 as compared with a theoretical molecular weight of 2628.'

' Example 4a The diol employed and theamount were: the

same as in Example 1a, preceding. The amount of catalyst employed was a little less than one pound, i.- e., 14 ounces. added was 58 pounds. the oxide was 7 hours with an added 1 hours for stirring. At the end of the reaction the molecular weight, based on hydroxyl value, was 1685 compared with a theoretical molecular weight of 3208.

Erampie 5a Example 60.

The diol employed and the amount were the same as that used in Example 111, preceding. The amount of caustic added as a' catalyst was one pound. The amount of propylene oxide was 81.2 pounds. The time required to add the'oxide was 12 hours. Thereaction mass' was stirred for 6 hours afterwards. The final product showed a molecular weight based on hydroxyl value of2005 as compared with a theoretical molecular weight of 4368.

Example 7a The diol employed and the amount was the same as in Example 1a. The amount of catalyst added was 1.25 pounds. The amount of oxide added was 92.8 pounds. The time required to add the oxide was hours and stirring was continued for 5 hours afterwards to complete the reaction. The molecular weight of the final product, based on the hydroxyl value, was 2085 compared with 4950 theoretical molecular Weight.

Example 811 In this instance a -gallon autoclave similar in construction and equipment to the 5 and 15- gallon sizes previously described, was used. The only difference in this autoclave was that the lower third of the autoclave could be heated separately from the upper two-thirds by two entirely distinct electrical circuits. For this reason, only the lower heating circuit was used during the addition of the first one-fifth'of pro pylene oxide (2. little over 23 pounds). There after, both circuits were employed and the autoclave was used as if the entire electrical heating system consisted of only one circuit.

The amount of oxide: The time required to add;

The time required to add- The diol and amount employed were the same as in Example 1a. The amount of catalyst.

added was 1.50 pounds; The amount of oxide added was 116 pounds. The time required to add the oxide was 18 hours. 'The reaction mass was then'stirred for 6 hours longer to insure completeness of reaction. The molecular weight.

of the final product, based on the hydroxyl value, was 2230 whereas the theoretical molec-} ular weight was 6108.

' Example 9a The diol employed was the glycidyl ether'ioftripropyleneglycol'N butyl tether. One mole of the monohydric ether. was reacted in presence of 2% sodium methylate with one mole of glycide until the reaction was-complete. The resultant product, as'previously noted, is the glycidyl ether". Its 'molecular'weightwas 322. The procedure employed,

of tripropy-lehe glycol N-butyl ether.

using the '5-gallon! autoclave, was'the same as in Example 10a, preceding. 6.45 pounds ofthe glycidyl' ether previously referred to were charged into-the autoclavaalong with .50 pound of sodiumhydro'xide; From this point on the' reaction was conducted in the same manner asin Example 1a, preceding. This applies to the time factor, the pressure factor, etc. The amount of oxide employed was the same as'in Example 1d, towit, 23.20 pounds. pletion of the reaction the molecular weight based on the hydroxyl value determination was 900, compared with 'a theoretical molecular weight of 1482. The final product was water v soluble, xylene-soluble and somewhat dispersible' However, the bulk of the product in kerosene. was kerosene-insoluble.

Example 10 'In this-example, and in the next five examples- (llathr'ough 15a, inclusive), the autoclave used was the 15-gallonand not the 5-gallon autoclave. The equipment and design of this15-gallon sizewas the same'as that'of the 5-gallon autoclave.

The same procedurewasffollowed as in Ex amples la and 9a, preceding. The initial charge was identical with that employed in Example 9a. The amount of catalyst added was the same as in Example 2a, and the amount of propylene oxide used was the same as in Example "2a, namely 34.80 pounds. The time period, etc., was same-as. in Example 2a.

The molecular weight, based on hydroxyl deitermination, was 1150 compared with a theoret ical molecular weight of 2062. The product was water-insoluble, xylene-soluble and kerosenesoluble. This statement applies to the next six examples andwill not be repeated.

Incidentally, the appparance of all these products (Examples 9:! through 1642.) was thefsame as in the previous'series of Examples la'through 8a, inclusive.

Example 11a The diol employed and amount was identical with that described in Example 9a. The amount of catalyst employed was 12 ounces. The

amount of propylene oxide added was the same as that employed in Example 311, preceding, i.- e., 46.4 pounds. The time period was 6 hours with an added hour for stirring. The conditions of temperature and pressure were the same as in preceding examples and, as a matter of fact, applies to all subsequent examples in this series, i. e., Examples ma-through 16a, inclusive, so this informationwillnot be repeated.

At the com' 1 1 The final product showed a. molecular weig'ht, based-on hydroxyl number, of; 1335 as comparedto -a theoretical molecular weight. of 254.2.

E mate. 1.2a.

The same. procedure wasi llowedes in. the precedin x mp s-j "Ihediol (.1 amount em; p ayed was dentical. with; that: Exam le: 9%. Theamountofcata' ystusedwas one-pound. am unt: propylene oxide. added. was. 9.1101; de- The i e of addi i n. e c-,vwas: the same. xample 5 precedin "The final produc showed a molecular wei ht; of. 11 bas.ed.on;.hydroxyl value. as. com ar d w th heoretical. molecular wei htoi' 3 92..-

E a ple lea The dial. mp oyed and. the amount were the ame as nhx rhple 9a precedin at or caus c addeds amounto propylene oxide wa 8. 1 pounds. T.....-t.iirie e er th s mea in Examp to,

Example a The diol employed and the amount was the s me a Exampl 5% amouhtoi: ,eatalys added wast-Z5 pounds. added was 9 .pouiitis. Th rea. was on= quo ed as tar as t m per od. goes. the samenehn r-as described, iIl'EX. ple 7e preceding. The mo ec ar we ght of. h

the hydroxyl V5 ,W@$.-Z:l.QQ

the theoretical. molec lar we h tor i .I

Example 16a In. inst nc a 2Q=eal1onauteo1ave.. similar inco struetioh and e u pment t .he i eal oh. a 1 -s sizes pr v y desor. .Was. used lhe on y difference in. th s au oelavew. s. that th low th rd o he aut clave eouldhe heat d separate y rom the up er two-thir s by twoentire .i t not elec r cal rcu this re.a ..only the. lowe hea n irc i asused during the. t on. oi the first one-fifth. of, the. p op lene oxide (a. lit le ver ounds Thereafter bot c rcuits. were emplo ed and the.- autoclave. was 1. ii-the entire. eIectrioa heating.systemeohsistedei only one circuit.

The diol and amount employed was the same as in Example 9a, preceding. The amount of catalyst employed L neunds; The amoun f oxide addedwas 1. ounds. time equired t add t e ide wa .8. ours reaction mas was stirred; io iii-hours. lon er-to. insure-completeness o r action. s. substantia ly the same. time per d. as used. i Examp e 8e. preceding. Th m lecular-we ht o the anal. product was 2210, ho ed th ydroxyl 'va1u.e,;and the theoretical mo e ul wei ht wasfilzh.

Numerous other examples. have been treated in he same m nner with pr pylene oxide. Such examples were; obtained; by treatmaalcohols. of

the kind descri ed, parti ularly ater sol -lblQ al a. polyethyle lyc l ther of, the sam k nd. In.

all instances such monohydrig; glycol others were then treated with e ide mole. f r m le-i preseheeo a sma amouhtofal ah ie ca alyst.

The dio e he so ob a ned was. thehsubiee edto oxypropylation in the manner illustrated in Examples 1a through 16a, preceding.

Thesolubilityof these products varied somewhat.- but. in. each instance water-insoluble and.

kerosene-:soluble products were obtained of actual molecular weights of 1,000 or in excess. thereof such as 12.00, 130.0, 1.400, or.thereabouts..

Speaking-of insolubility in Water or solubility in kerosene such solubilitytest can be made. sim-.-. p y bith in small amounts of the mater a s. in a, test tubev with water, for instance, using l to 5% approximately based on the amount'of water present.

Needless to say, there is no complete conversion oipropylene oxide into the desired hydroxylated compounds. This is indicated by the fact that the theoretical molecular weight based on a statistical average is greater than the molecularweight calculated by usual methods on basis; of acetyl or hydrox-yl value. Actually, there is no; completely satisfactory method for determining molecular weights of these; types of compounds with a high degree of accuracy when the, molege ular-weights exceed 2,000. In someinstances the acetyl value or hydroxyl value.- servesas satise actorily as an dex t th mo ecular w i htas any other procedure, subject to the above limitations, and especially in the higher molecular Weight range. If any. difficulty. is encounteredain the manufacture of the esters. as described Bar-t Zthe stoichiometrical amount of acid or acid compound should be taken which corresponds to. the indicated acetyl' or hydroxyl value; matterhas been discussed in the literature and is av matter of common knowledge and requires no-further elaboration. In fact, it-is illustrated by some. of theexamples appearing in the patent previously mentioned.

PART 2' A pr v usly pointe t he re en invention s co c ned. with ac c ester o ined iroh the oxyp y a e d r ative d s i ed i Part 1. mmediate pr eed hs d ho a rbo y ids pa tic a ioarhox a ids s as pi acid phthal acid... or anhydri e suooin a id. di ly collie aci seb io acid aze a o acid. a'coni ic cid. ma a d or a dri eitr oniea id or anhydride, maleic acid or anhydride adducts as obtained by the Diels-Alder reaction from reactants such as maleic anhydride and cyclopeiltailiene. Such acids should be heat stable'so they are not. decomposed during esterification. They may contain as many as 36 carbon atoms as, for example, the acids obtained by dimerization of unsaturated fatty acids, unsaturated monocarbox'y fatty acids, or unsaturatedmonocarboxy acids. having 18 carbon atoms. Reference to the acid in the hereto appended claims obviously includes the anhydrides or any other obvious equivalents. My preference, howeyer; is to use polycarboxy acidshaving not over 8 carbon atoms. K

The production of esters including acid ester-s (fractional esters) from polycarboxy acids and glycols or other hydroxylated compounds is well known. Needless to say, various compounds may be used such as the low molal ester, the anhydride, the acyl chloride, etc. However, for purpose of economy it is customary to use either the acid or the anhydride. A conventional procedure is employed. On a laboratory scale'one can employ a resin pot of the kind described in U. S. Patent No. 2,499,370, dated March '7, 1950, to De Grocte and Keiser, and particularly with one more opening to permit the use of a porous spreader if hydrochloric acid gas is to be used as a catalyst. Such device or absorption spreader consists of minute alundum thimbles which are connected to a glass tube. One can add a sulfonic acid such as para-toluene sulfonic acid as-a catalyst. There is some objection to this because in some instances. there is some evidence that this acid catalyst tends to decompose or rearrange oxypropylated compounds, and particularly likely to do so if the esterification temperature is too high. In the case of polycarboxy acids such as diglycollic acid, which is strongly acidic there is no need to add any catalyst. The

use of hydrochloric gas has one advantage over' para-toluene sulfonic acid and that is that at the end of the reaction it can be removed by flushing out with nitrogen, whereas there is no reasonably convenient means'available of removing the paratoluene sulfonic acid or other s'ulfonic acid employed. If hydrochloric acid is employed one need only pass the gas through at an exceedingly slow rate so as to keep the reaction mass acidic. Only a trace of acid need be present. I have employed hydrochloric acid gas or the aqueous acid itself to eliminate the initial basic material. My preference, however, is to use no catalyst whatsoever and to insure complete dryness of the diol as described in the final procedure just preceding Table 1.

The products obtained in Part 1 preceding may contain a basic catalyst. As a general procedure I have added an amount of half-concentrated hydrochloric acid considerably in excess of what is required to neutralize the residual catalyst. The mixture is shaken thoroughly and allowed to stand overnight. t is then filtered and refluxed with the xylene present until the water can be separated in a phase-separating trap. As soon as the product is substantially free from water the distillation stops. This preliminary step can be carried out in the flask to be used for esterification. If there is any further deposition of sodium chloride during the reflux stage needless to say a second filtration may be required. In any event the neutral or slightly acidic solution of the-oxypropylated derivatives described in Part 1 is then diluted further with sufiicient xylene decalin, petroleum solvent, or the like, so that one has obtained approximately a 65% solution. To this solution there is added a polycarboxylated reactant as previously described, such as phthalic anhydride, succinic acid or anhydride, diglycollic acid, etc. The mix ture is refluxed until esterification is complete as indicated by elimination of water or drop in carboxyl value. Needless to say, if one produces a half-ester from an anhydride such as phthalic anhydride, no water is eliminated. However, if it is obtained from diglycollic acid, for example, water is eliminated. All such procedures are conventional and have been so thoroughly described in the literature that further consideraresidual basic catalyst. To this product one can then add a small amount of anhydrous sodiumsulfate (sufiicient in quantity to take up'any water that is present) and then subject the mass to centrifugal force so as to eliminate the hydrated sodium sulfate and probably the sodium chloride formed. The clear somewhat viscous straw-colored amber liquid so obtained may con-- tain a small amount of sodium sulfate or sodium chloridebut,'in any event, is perfectly acceptable for esteriflcation in the manner described.

It is to be pointed out that the products here described are not polyesters in the sens'ethat there is a plurality of both diol radicals andiacid radicals; the product is characterized by hay-- ing only one diolradical.

In some instances and, in fact, in many instances I have found that in spite of the dehydra tion methods employed above that a mere trace of waterstill comes through and that this mere trace of water certainly interferes with the acetyl or hydroxyl value determination, at least when a number of conventionalprocedures are used and may retard esterification, particularly where there is no sulfonic acid or hydrochloric acid present as a catalyst. Therefore, I have preferred to use thefollowing procedure: I have em ployed about 200 grams of the diol. as described in Part 1, preceding; I have added about 60 grams of benzene, and then refluxed this mixture in the glass resin pot using a phase-separating trap until the benzene carried out all the water present as water of solution or the equivalent. Ordinarily this refluxing temperature is apt to be in the neighborhood of 130 to possibly 150 C. -When all this water or moisture has been removed I also withdraw approximately 20 grams or a little less benzene and then add the required amount of the carboxy reactant and also about 150 grams of a..- high boiling aromatic petroleum solvent. These solvents are sold by various oil refineries and, as far as solvent effect act as if they were almost completely aromatic in character. Typical distillation data in the particular type I have em-. ployed and found very satisfactory is the follow-. ing: 1

ml., 242C.

5 ml., 200 c. ml., 244 c. 10 ml., 209 0. e0 1111., 248 0. 15 ml., 215 0; ml., 252 0. 1 .20 ml., 216 0. ml., 252 0. 25ml; 220C. ml, 260C. 30 ml., 225 '0. ml., 264 0. 35 ml., 230 ml, 270 0. 40 ml., 234C. ml., 280 c. 45 ml.', 237 0. ml., 307 0.

After this material is added, refluxing fisv coni tinued and, of course, is at a high temperature, to wit, about to C. If the carboxy r'e-' actant is an anhydride needless to say no water of reactionappears; if the carboxy reactant is an acid water of reaction should appear and should be eliminated at the above reaction ternperature. If it is not eliminated I simply separate out another 10 or 20 cc. of benzene by means few'examples and a'com- 'th ha e separatine trap. and thus. raise the TABLE 2 temperature to 180 or 190 0., 01: e to 200, C.,

if needv be. My; preference is 1100150,; go above EX N of Amt. Esterifica- Time 51 Water C 1 E Solvent Solvent tion Esterifica- Out (grs.) Temp, C. tio11(hrs.) (cc.)

/ The use efsuch solvent is. ex remely setlsfac tory provided one does not attempt-to remove the 289 169 4% 8.1 solvent subsequent-1y except by vaeuum-distilla- 278 115 3% None tion and provided there is; no, objection to a little ggg 6 residue. Actually, when; these materials are used 200 9 0 for 'purnose such as de ulsifieeti nth sol en 223 13g 2? 83 might; iustas, well bev allowed to remain. If the 240 144 1 None solvent. is .to b r m ved. by di tillation. and par- 33% t3? 1% icularly vacuum, (1' illation. then he hi h h l- 248 155 4 83 me aromatic petre 11m. s lv n mi ht. we11 e'reggg fig 2 g3 n aced y some m re expensive s lve t. s ch as 255 147 2 None deealin r analkvlated deca in which has a 5;; 1, ,2 2 95 rather definite or close range boiling point. The 252 157 314 5 7 remo al o the s ivent. ofeou seis pur y a on- 318 $3 22 vention l proce ur nd requi n la ti n 255 155 1 None In-the. appe ded.- able Solvent 3.which. 211: 5:5 133 g -3 peers in. allinstan s s. a mix reof 7 v lum 252 158 3 5Z2 efine-aromati pe r um. s lv previously d ggg {g3 f f3 eeri ed. and. 3 lumes of b nz ne- This was 220 115 1 N55 s d. r a. sim lar m xture. 111 the manner pre-- 3% 12% N0 1: viously described. In a large number of similar 255 159 a 3.5 xamples; de alin een d. but itis my pr ggg 1 ,33 if; 5-1 erence'to use the above mentioned mixture and 230 154 1% None particularly with. the pre i inarystep f remov- 253 113 the all the-water. Ifone does not; intend to re- 277 152 29 moveqt-he solvent mypreference is to use the 2 petroleum solvent-benzene mixture although 0b- 242 155 124 None viously any of the other mixtures, such as deealin 1 g: and xylene, can'be employed. 120 2% 3 0 The data included in the subsequent tables, 2 3 26 i. e.,' Tab1es 1 and 2, are selfeexplanatory, and very 35 complete.v and it is believedno further elabora- The procedure for manufacturing the'estejqg nears-necessary: has been illustrated by preceding examples. If

, 1 Amount vEx. No. of of Hydroxy Amt. EnNO-OI 5 Bdrm. Awgstiet olgig adrgggd 010181121. by i i Polycarboxy Reactant 1 v Deferm Used (grs.)

2 1,125 225 Adipic Acid 58 211 1,125 225 P-hthalic Anhydride 59 2a 1,125 225 Succinic Anhydride 40 22 1,125 225 75 '20 1,125 225 54 211 1,125 225 7 311 1 1,575 275 'p' 55 30, 1,375 275 Phthalic Anhydride 59 311; 1,375 5 275 Succinic Anhydr-ide 40 3a 1,375 275 Azelaic Acid 75 3a 1, 375 275 Diglycollic Acid 54 3a 1, 375 27,5 Ac011iticAcid. 70 4a 1, 055 28 1 Adipie Acid... 411 1,685 251 P11152115 111111 7011115.-. 49 4a 1, 685 281 Succinic Anhydride 33 412 1,685 281 Azelaic Acid 63 411 1,685 281 Diglycollic Acid 45 I 411 1,685 281 Aconitic Acid 58 50 1,820 182 Adipic Acid---. 29 1 1,820 152 P51112115 11111 17111105.-. 30 512 1,820 182 -SuccinicAnl1ydride 20 5o 1, 820 182 Azelaic Acid 38 5a 1,820 182 Diglycollic Acid 27 52 I 1,820 152 55 011 2,005 200 29 511 2,005 200 30 2,005 200 20 6a 5 2,005 200 Azc1aicAcid 38 011, 2,005 200 .Diglycoliic Acid 27 6a 2, 005 200 Aconitic Acid 35' 71; 2,085 208 Adipic Acid 29 2,085 208 P11155115 Anhydri so 71 2, 085 208 Succinic Anhydride 20 7a 2,085 208 Azelaic Ac 38 70 2, 08 5 208 DiglycollicA 27 701, 2, 55 208 15511111015111- 55 512 2,230 225 Adipic Acid. 29 8 a 2, 230 223 Pl thalic Anhydride 30 82, 2,230, 223 Succiuic Anhydride. 20 2,230 223 Azelaic Acid 38 8a 2, 230 223 Diglycollic Acid. 27 8a 2, 230 22 3 Acom'ticAcid 35.,

acoaoce for any reason reaction does not take place in a manner that is acceptable, attention should be directed to the following details: (a) Recheck the hydroxyl or acetyl value of the oxypropylated glycerol ether and use a stoichiometrica'lly equiv alent amount of acid; (b) if the reaction does not proceed with reasonable speed either raise the temperature indicated or else extend the period of time up to 12 or 16 hours if need be; (c) if necessary, use /2% of paratoluene sulfonic acid or some other acid as a catalyst; (d) if the esterification does not produce a clear product a. check should be made to see if an inorganic salt such as sodium chloride or sodium sulfate is not precipitating out. Such salt should be eliminated, at least for exploration experimentation, and can be removed by filtering. Everything else being equal as the size of the molecule increases thereactive hydroxyl radical represents a smaller fraction of the entire molecule'and thus more difliculty is involved in obtaining complete esterification.

Even under the most carefully controlled conditions of oxypropylation involving comparatively low temperatures and long time of reaction there are formed certain compounds whose compositions are still obscure. Such side reaction products can contribute a substantial proportion of the "final cogeneric reaction mixture. Various suggestions have been made as to the nature of these comp'oundasuch as being cyclic polymers of I propylene oxide, dehydration products with the appearance of a vinyl radical, or isomers of propylene oxide or derivatives thereof, 1. e., of an aldehyde, ketone, or allyl alcohol. In some instances an attempt to react he 'stoichiometric amount of a polycarboxy acid with the oxypropylated derivative results in an excess of the carboxylated reactant for the reason that apparently under conditions of reaction less reactive hydroxyl radicals are presentthan indicated by the hydroxyl value. Under such circumstances there is, simp'lya residue of the carboxylic reactant which be removed by filtration or, if desired, the esterification procedure can be repeated using an appropriately reduced ratio of carboxylic reactant. V

Evenpthe determination of the hydroxyl value and conventional procedure leaves much to be desired-due eitherto the cogeneric materials. previously referred to, or for that matter, thepresence of any inorganic salts or propylene oxide. Obviously this oxide should ice-eliminated.

The solvent employed, if any, can be removed I color, and show moderate viscosity. They can be bleached with bleaching clays, filtering chars, and the like. However, for the purpose of demulsification or the like color is not a factor and decolorizationis not justified.

. In: the above instances I have permitted the solvents to remain. present in the final reaction mass; In other instances I have followed the and give cleaner oil in many instances.

18 PART 3 Previous reference has been made to the fact that diols such as polypropyleneglycol of approximately. 2,000 molecular weight, for example, have been esterified with dicarboxy acids and employed as demulsifying agents. On first examination the difference between the. herein described products and such comparable products appears to be rather insignificant. In fact, the difference is such that it fails to explain the fact that compounds of the kind herein described may be, and frequently are, 10%, or better on a quantitative basis than the simpler compound previously described, and demulsify faster The method of making such comparative tests has been described in a booklet entitled Treating Oil Field Emulsions, used in the Vocational Training Course, Petroleum Industry Series, of the American Petroleum Institute.

The difference, of course, does not reside in the carboxy acid but in the diol. Momentarily an effort will be made to emphasize certain things in regard to the structure of a polypro-' pylene glycol, such as polypropylene glycol of a 2000 molecular weight. Propylene glycol has a primary alcohol radical and a secondary alcohol radical. In this sense the building unit which forms polypropylene glycols is not symmetrical. Obviously, then, polypropylene glycols can be obtained, at least theoretically, in which two secondary alcohol groups are united or a secondary alcohol group is united to a primary alcohol group, etherization being involved, of course, in each instance.

Usually no effort is made to differentiate between oxypropylation taking place, for example, at the primary alcohol unit radical or the secondary alcohol radical. Actually, when such products are obtained, such as a high molal polypropylene glycol or the products obtained in the same procedure -using decalin or 7 a mixture of manner herein described one does not obtain a single derivative such as HO(RO)nH in which n has one and only onevalue, for instance, 14, 15 or 16, or the like. Rather, one obtains a cogeneric mixture of closely related or touching homologues. These materials invariably have high molecular weights and cannot be separated from one another by any known procedure without decomposition. The properties of such mixture represent the contribution of the various individual members of the mixture. On a statistical basis, of course, n can be appropriately specified. For practical purposes one need only consider the oxypropylation of a monohydric alcohol because in essence this is substantially the mechanism involved. Even in such instances where one is concerned with amonohydric reactant one cannot draw a single formula and say that by followingsuch procedure one can readily obtain or or of such compound. However, in the case of at least monohydric initial reactants one can readily draw the formulas of a large number, of compounds which appear in some of the probable mixtures or can be prepared as componentsand mixtures which are manufac-.

me sa e: any such "simple hydroxylated com aet'acee tion, such as oxyethylation, or. oxypropylation, it

becomes obvious that one is really producing a polymer of the alkylene' oxides except for the terminal group. This is particularly true where the amount of oxide added is comparatively large, for instance, 10, 20,- 30, 40,v or 50 units. If such compound is subjected to oxyethylation so as to introduce 30 units of ethylene oxide, it is well known that one does not obtain a single constituent which, for the sake of convenience, may be indicated as RO C2H4O 30I-L Instead, one obtains a cogeneric mixture of closely related homologues, in which the formulamay' be shown as the following, nolczrnonn, wherein n, as far as the statistical average goes, is .30, but the individual members present in significant amount may vary from instances where n has a value of 25, and perhaps less, to a point where n may represent 35 or more. Such mixture is, as stated, a cogeneric closely related series of touching homologous compounds. Considerable investigation has been made in regard to the distribution curves for linear polymers. Attention is directed to the article entitled Fundamental principles of condensation polymerization, by Flory, which appeared in Chemical Reviews, volume 39, No. 1, page 137.

Unfortunately, as has been pointed out by Flory and other investigators, there is no satisfactory method, based on either experimental or mathematical examination, of indicating the exact proportion of the various members of touching homologous series which appearin cogeneric condensation products of the kind de-' scribed. This means that from the practical standpoint, i. e., the ability to describe how to make the product under consideration and how to repeat such production time after time without difiiculty, it is necessary to resort to some other method of description, or else consider the value of n, in formulas such as those which have appeared previously and which appear in the claims, as representing both individual constituents in which n has a single definite value, and also with the understanding that n represents the average statistical value based on the as-' sumption of completeness of reaction.

' This may be illustrated f as follows: Assume that in any particular example the molal ratio of the propylene oxide to the diol is 15' to 1.

Actually, one obtains products in which 1?. probably varies from to 20, perhaps even further. The average value, however, is assuming, as previously stated, that the reaction is complete. The product described by the formula is best described also in terms of method of manufacture.

However, in the instant situation it becomes H- R'o R"o oH H O O H H 1 in which the variouscharacters have their previous significance. v v I vioiis that one now has a no'nsymmetri'cal rad ical in the majority of cases for increased that in the cogeneric mixture going back to thecorresponding formula n and n are usually not equal. For. instance,.

if one introduces 15 moles of propylene oxide, n and n" could not be equal, insofar that the nearest approach to equality is where the value of n is 7 and. 1L is 8. However, even in the case of an even number such as 20, 30, 40 or 50, it is also obvious that n and n will notbe equal in light of what has'been said previously. Both sides of the molecule are not going to grow with equal rapidity, i.e., to the same size. Thus the diol herein employed is differentiated from polypropylene diol 2000, for example, in that (a) it carries a hereto unit, i. e., a unit other than a propylene glycol or propylene oxide unit, (6) such unit is off center, and (c) the effect of that unit, of course, must have some effect in the range with which the linear molecules can be drawn together by hydrogen binding or van der Waals forces, or whatever else may be involved.

What has been said previously can be emphasized in the following manner. It has been pointed out previously that in the last formula immediately preceding, 11 or n could be 'zero.v

glycerol ether is esterified with a low molal acid I such as acetic acid mole for mole and such prodnot subjected to oxyalkylation using a catalyst, such as sodium methylate and guarding against the presence of any water, it becomes evident that all the propylene oxide introduced, for instance 15 to molecules per polyhydric al-' cohol molecule necessarily must enter at one side only. to decompose the acetic acid ester and then acidified so as to liberate the water-soluble acetic acid and the water-insoluble diol a separation can be made and such diol then subjected to esterification as described in Part 2, preceding. Such esters, of course, actually represent products where either n or n is zero. Also intermediate procedures can be employed, i. e., following the same esterification step after partial oxypropylation. For instance, one might oxypropylate with one-half the ultimate amount of propylene oxide to be used and then stop the reaction. One could then convert this partial oxypropylated intermediate into an ester by reaction of one mole of acetic acid with one mole of a diol. This ester could then be oxypro pylated with all the remaining propylene oxide. The final product so obtained could be saponi-e;

fied and acidified so as to eliminate the water-- diates and high molal polypropylene glycol, such as polypropylene glycol 2000.

If such product is then saponified so as.

aeoaocc 21 PART 4 Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, or after dilution with any suitable solvent, such as water, petroleum hydrocarbons, such as benzene, toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc., may be employed as diluents. Miscellaneous solvents such as pine oil, carbon tetrachloride, sulfur dioxide extract obtained in the refining of petroleum, etc.-, may be employed as diluents. Similarly, the material or materials employed as the demulsifying agent of my process may be admixed with one or more of the solvents customarily used in connection with conventional demulsifying agents. Moreover, said material or materials may be used alone or in admixture with other suitable well-known classes of demulsifying agents.

It is well known that conventional demulsifying agents may be used in a water-soluble form, or in an oil-soluble form, or in a form exhibiting both oiland water-solubility. Sometimes they may be used in a form which exhibits relatively limited oil-solubility. However, since such reagents are frequently used in a ratio of l to 10,000 or 1 to 20,000, or 1 to 30,000, or'even 1 to 40,000 or 1 to 50,000 as in desalting practice, such an apparent insolubility in oil and water is not.

significant because said reagents undoubtedly have solubility within such concentrations. This same fact is true in regard to the material or materials employed as the demulsifying agent of my process.

In practicing my process for revolving petroleum emulsions of the water-in-oil type, a treating agent or demulsifying agent of the kind above described is brought into contact with or caused to act upon the emulsion to be treated, in any of the various apparatus now generally used to resolve or break petroleum emulsions with a chemical reagent, the above procedure being used alone or in combination with other demulsifying procedure, such as the electrical dehydration process.

One type of procedure is to accumulate a volume of emulsified oil in a tank and conduct a batch treatment type of demulsification procedure to recover clean oil. In this procedure the emulsion is admixed with the demulsifier, for example by agitating the tank of emulsion and slowly dripping demulsifier into the emulsion. In'so'me cases mixing is achieved by heating, the emulsion while dripping in the demulsifier, depending upon the convection currents in the emulsion to produce satisfactory admixture. a third modification of this type of treatment, a circulating pump withdraws emulsion from, e. g., the bottom of the tank, and reintroduces it into the top of the tank, the demulsifier being added, for example, at the suction side of said circulating pump.

In a second type of treating procedure, the demulsifier is introduced into the well fluids at the well-head or at some point between the wellhead and the final oil storage tank, by means of an adjustable proportioning mechanism or proportioning pump. Ordinarily the flow of fluids through the subsequent lines and fittings sufiices to produce the desired degree of mixing of demulsifier and emulsion, although in some instances additional mixing devices may be introduced into the flow system. In this general procedure, the system may include various-mechanical devices for withdrawing free water, separating entrained water, or accomplishing quiescent settling of the chemicalized emulsion. Heating devices may likewise be incorporated in any of the treating procedures described herein.

A third type of application (down-the-hole) of demulsifier to emulsion is to introduce the demulsifier either periodically or continuously in diluted or undiluted form into the well and to allow it to come to the surface with the well tion of emulsion, admixing the chemical and emulsion either through natural flow or through special apparatus, with or without the application of heat, and allowing the mixture to stand quiescent until the undesirable water content of the emulsion separates and settles from the mass.

The following is a typical installation.

A reservoir to hold the demulsifier of the kind described (diluted or undiluted) is placed at the well-head where the efliuent liquids'leave the well. This reservoir or container, which may vary from 5 gallons to 50 gallons for convenience, is connected to a proportioning pump which injects the demulsifier drop-wise into the fluids leaving the well. Such chemicalized fluids pass through the flowline into a settling tank. The settling tank consists of a tank of any convenient size, for

instance, on which will hold amounts of fluidproduced in 4 to 24 hours (500 barrels to 2000 barrels capacity), and in which there is a perpendicular conduit from the top of the tank to almost the very bottom so as to permit the in-' coming fluids to pass from the top of the settling tank to the bottom, so that such incoming fluids do not disturb stratification which takes place during the course of demulsification. The settling tank has two outlets, one being below the water level to drain off the water resultlngfrom demulsification or accompanying the emulsion as' free water, the other being an oil outlet at the topto permit the passage of dehydrated oil to a second tank, being a storage tank, which holds pipeline or dehydrated oil. If desired, the con duit or pipe which serves to carry the fluids from the well to the settling tank may include acsection of pipe with battles to serve as a mixer, to insure thorough distribution of the demulsifier throughout the fluids, or a heater for raising the temperature of the fluids to some convenient temperature, for instance, to F., or both heater and mixer.

Demulsification procedure is started by simply setting the pump so as to feed a compara tively large ratio of demulsifier, for instance, 115,000. As soon as a complete break or satisfactory demulsification is obtained, the pump.

is regulated until experience shows that the amount of demulsifier being added is just suilicient to produce clean or dehydrated oil. The

amount being fed at such stage is usually 1 10,000,

l:l5,000, l:20,000, or the like.

Inmany instances the oxyalkylated products rei sp c fie aa l mul e ts s parts by weight of isopropyl alcohol, an exceelen't'd'emul'sifie'r is obtained. Selection of the solvent will vary, depending upon the solubility characteristics of the oxyalkyl'at'ed' product, and of course will be dictated in part by economic considerations, i. e., cost. I

As noted above, the products herein describedmay' be used not only in diluted form, but also may be used admixed with some other chemical de'm'ulsifier;

- PART Previous reference has been made to other oxyalkylating agents other than propylene oxide, such as ethylene oxide. Obviously variants can be prepared which do not depart from whatis said herein but do produce modifications. The diol derived by etherization of glycerol in the manner described can be reacted with ethylene oxide in modest amounts and then subjected to oxypropylation provided that the resultant derivative is (a) water-insoluble, (b) kerosene-soluble, and (c) has present to 80 alkylene oxide radicals. Needless to say, in order to have waterinsolubility and kerosene solubility the large majority must be propylene oxide; Other variantssuggest themselves as, for example, replacing. propylene oxide by butylene oxide.

More specifically then one mole of such etherized glycerol of the kind described can be treated with 2, 4 or 6 moles of ethylene oxide and thentreated with propylene oxide so as to produce a water-insoluble, kerosene-soluble diol in which there are present 15 to 80 oxide radicals as previously specified. Similarly the propylene oxide can be added first and then the ethylene oxide}. or random oxyalkylation can be employed using a mixture of the two oxides. The compounds so obtained are readily esterified in the same manner as described in Part 2, preceding. Incidentally, the diols described'in Part 1 or the modifications described therein can be treated with various reactants such as. glycide, epichlorohydrin, dimethyl sulfate, sulfuric acid, maleic anhydride, ethylene imine, etc. If treated with epichlorohydrin or monochloroacetic acidthe resultant product can be further reacted with a tertiary amine such as pyridine, or the like, to give quaternary ammonium compounds. If treated with maleic anhydride to give a total ester the resultant can be. treated with sodium bisulfiteto yield a sulfosuccinate. Sulfo groups can be introduced also by means of a sulfat'ing agent as previously suggested, or by treating the chloroacetic acid resultant with sodium sulfite.

I have found that if such hydroxylated compound or compounds are reacted further so as to produce entirely new derivatives, such new derivatives have the properties of the original hydroxylated compounds insofar that they are effective" and valuable demulsifying agents for resolution of water-in-oil emulsions as found in the petroleum industry, as break inducers in com tor treatment of sour crude, etc. i I

Having thus described my invention, what 1 claim as new and desire to secure by Letters Patcut, is

l. A process for breaking petroleum emulsions of the water-in oil type characterised by subletting the emulsion to the action of a demul'si- 24 fier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the. following formula:

in which n and n are numerals including zero; and n' is. a small whole number less than 10, with the proviso that n plus n plus 12' equals a sum varying. from 15 to and n" is a whole number not over 2; R is an alkylene radicalhaving 2 to-B carbon atoms; R. is a hydrocarbon" radical having less than '8 carbon atoms, and R is a radical of the polycarboxy acid een in which n" has its previous significance; and with the further proviso that the parent diol prior to esterification be water-insoluble and kerosene soluble.

2. A process for breaking petroleum emulsions of the wat'er-in-oil type characterized by subjecting the emulsion to the action of a demulsifier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula:

and n is a small whole number less than 19-, with the proviso that it plus it plus n equals a sum varying from 15 to 80 and n" is a whole' in which n" has its previous significance; said polycarboxy acid having not more than 8 carbon atoms; and with the further proviso that the parent diol prior to esterification be water-insol uble and kerosene-soluble. I

3. A process for breaking petroleum emulsions of the water-in-oil type characterized by sub jectingi the emulsion to the action of a demsulifierincluding hydrophile synthetic products; said nydrophile. synthetic products being character ized by the following formula:

in which n and n are numerals excluding zero and n is a. small whole number less thanlO, with the proviso that 11 plus 11 plus n equals a sum varying. from 15 to 80 andn" is a whole number not over 2; R" is an alkylene radical" having to 3 carbon ani als is a hydrocarbon 25 radical having less than 8 carbon atoms, and R is a. radical of the polycarboxy acid COOH in which n and n are numerals excluding zero, and n is a small whole number less than 10, with the proviso that n plus m plus 71 equals a sum varying from 15 to 80; R" is an alkylene radical having 2 to 3 carbon atoms; R is a hydrocarbon radical having less than 8 carbon atoms, and R is a radical of the dicarboxy acid coon COOH said dicarboxy acid having not more than 8 carbon atoms; and with the further proviso that the parent diol prior to esterification be waterinsoluble and kerosene-soluble.

5. The process of claim 4 wherein R has at least 3 carbon atoms.

6. The process of claim 4 wherein R has at least 3 carbon atoms and is derived from a watersoluble alcohol.

7. The process of claim 4 wherein R has at least 3 carbon atoms, is derived from a watersoluble alcohol, and the dicarboxy acid is phthalic acid.

8. The process of claim 4 wherein R has at least 3 carbon atoms, is derived from a watersoluble alcohol, and the dicarboxy acid is maleic acid.

9. The process of claim 4 wherein R has at least 3 carbon atoms, is derived from a watersoluble alcohol, and the dicarboxy acid succinic acid.

10. The process of claim 4 wherein R has at least 3 carbon atoms, is derived from a watersoluble alcohol, and the dicarboxy acid is citraconic acid.

11. The process of claim 4 wherein R has at least 3 carbon atoms, is derived from a watersoluble alcohol, and the dicarboxy acid is diglycollic acid.

MELVIN DE GROOTE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Blair Aug. 7, 1951 

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPE CHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIER INCLUDING HYDROPHILE SUNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETIC PRODUCTS BEING CHARACTERIZED BY THE FOLLOWING FORMULA: 